To estimate the prevalence of erosive tooth wear in children aged 12-17 years in the southwest region of San Antonio, Texas, within Bexar County. A convenience sample of 307 children aged 12-17 years was selected from two junior high schools. The population consisted predominantly of Hispanic Mexican Americans. The true prevalence of erosive tooth wear within the US is known from only one study, and then only for limited sectors of the population. The Tooth Wear Index, Screening for Oral Health using the Association of State and Territorial Dental Directors (ASTDD) criteria and oral health and dietary assessment questionnaires were used as survey parameters. The questionnaire included data on detailed dietary habits relating primarily to the consumption of acidic beverages and foods. The overall prevalence of erosion within our convenience sample was 5.5 percent. All affected children showed erosive tooth wear low in severity and confined to the enamel with no exposed dentin. A chi-square test was performed to test for associations between the presence of erosion and consumption level of certain acidic foods at a significance level of 5 percent. Few significant and consistent associations were found between erosive tooth wear and consumption frequency categories of groups of acidic foods and beverages using a non-validated food intake questionnaire on purported risk foods. Soda drinks were associated. Mexican acidic foods were not. This study indicated a low prevalence and low severity of dental erosion in a convenience sample of children aged 12-17 years in southwest San Antonio, Texas. Issues of sampling and response bias preclude these findings being generalized to other populations and regions.The results should be viewed with caution. Because the local consumption of some purported risk foods appears to be increasing, this study provides a base-line for future assessments of erosive tooth wear in this population.